


Battle Against a True Hero

by Heartcrystal2000



Series: Undyingtale [1]
Category: Undertale (Video Game)
Genre: Alternate Universe - Canon Divergence, Attempted Undertale Genocide Run, Eventual Romance, F/F, Fights, Gen, Past Character Death, Resurrection, Self-Hatred, Self-Sacrifice, Suicide Attempt, Temporary Character Death
Language: English
Status: Completed
Published: 2018-11-29
Updated: 2018-12-18
Packaged: 2019-09-02 01:45:31
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 8
Words: 8,036
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16777153
Author URL: https://archiveofourown.org/users/Heartcrystal2000/pseuds/Heartcrystal2000
Summary: "Battle Against a True Hero", takes place in the midst of the human's genocide. Desperate to keep the human from killing any more of her friends, Undyne sets out to strike them down. But the human's determination has made them much stronger than anyone was prepared for, and soon all hope seems lost. Luckily, a mysterious individual decides to lend Undyne a helping hand.





	1. The Wind is Howling (Undyne)

**Author's Note:**

> So, this is actually one of the first fanfics I’ve written, it’s actually from about two years ago! It started out as just a little writing exercise, but I got kind of attached to the story and it turned into a whole AU. I know this fanfic’s old, but I wanted to post it here since I have an account now.
> 
> (Like I said, it’s from two years ago. It’s not the best example of my writing, but it’s the first thing I finished so I’m still proud of it.)

The human stands in front of me with an annoyed expression on their face. "You just _had_ to get in the way, didn't you?"

"U-Undyne, you're hurt!" the young monster I just saved cries out. He steps in front of me protectively and says to the human, "Y-you stay away from her!"

I reach out a hand and gently push the child away from the human. "I'm fine, kid. I can take on this little human easily. You go home now, I'll finish this!"

The little yellow monster looks up at me, tears in his eyes, before turning and running away. As soon as he is gone, I slump over slightly--the searing pain making it hard for me to stand. Blood seeps from the deep wound on my torso. "Heh... 'it's nothing'?"

Slowly, I sink to my knees. The human stands over me, smiling smugly. "You aren't so strong now, are you?"

I can feel myself fading. I'm starting to turn to dust. "Asgore," I say to myself, "Papyrus, Sans, Alphys... I've failed you all..."

As I kneel there, dying, visions of my friends flash before my eye. I remember Asgore teaching me to fight. I see Sans telling puns and Papyrus building puzzles. I think of Alphys, who is likely watching me right now on one of her many cameras. " _No,_ " I think, " _I refuse to die like this. I have got to keep fighting. For my friends. For_ all _monsters._ "

I stop disintegrating. Deep in my soul, there is a burning feeling that won't let me die. Slowly, I get to my feet, leaning on my spear for support. The human stares at me and giggles. They tilt their head and look at me curiously. "Hmm. In all the time I have been down here I have never seen a monster with so much... _determination_. Fighting you should be an interesting challenge."

"You've killed my friends," I say, my voice quaking with rage. "You were about to murder an innocent kid! If you get past me, you'll destroy everyone else. But I won't let you do that." With each word I stand up taller, for I can feel everyone's hearts beating as one. " _All of the other monsters... they're counting on me,_ " I realize. " _I can't let them down!_ "

The human laughs. "You certainly have a fighting spirit, don't you? However, I'm afraid that there's no way for you to stop me."

I level my weapon at the human and yell at the top of my lungs, "I, UNDYNE, WILL STRIKE YOU DOWN!"

The burning feeling grows so intense that it seems as if I'm on fire. I feel myself changing--turning to dust and reforming. When the process is finished, I am different. My armor is repaired and the terrible wound is gone. A new energy courses through my veins, filling me with strength like I've never had before. I give the human a taunting grin and shout, "Ha! You're gonna have to try a little harder than THAT."

The wind howls through the blue stalactites of the cavern and a strange light suffuses the room. I start the fight by thrusting my spear at the human, trying to catch them off guard with a quick strike. They sidestep the attack and slash at me with their knife. Meeting no resistance, I stumble forwards a little ways and the sharp edge of the weapon slices deeply through a gap in my armor. I'm so focused on the battle that I hardly notice the pain.

Quickly, I spin around and send spears flying at the human. They dodge all but two and manage to score another hit with their blade. I keep attacking, and the human keeps dodging. " _They're pretty good at this,_ " I think. " _But what will happen if I change things up?_ "

I stand still for several moments, and the human takes a cautious few paces forward. Suddenly, I lunge at them. The spear point grazes the human's chest, and they step backwards before stopping abruptly. Their soul, which was once glowing red, is now a bright green. The human looks down at it and then back at me before remarking, "I was wondering when you were planning on doing that."

Now that they're immobile, I launch a volley of energy spears at the human. They snatch the first projectile out of the air and use it to block the rest. I summon more spears and send them flying, faster this time. Still, the human manages to use the spear they caught to deflect my attacks. I can tell this isn't working, so I swipe at the human with my weapon again and change their soul back to red before immediately sending more spears hurtling towards them from all directions.

The fight wears on, and the human doesn't even seem to be slowing down. Many of my projectiles find their mark, injuring them, and still they always get right back up. When they retaliate, their hits always land. " _Why can't I get away from their attacks? It's like they know exactly what I'm going to do!_ "

I can tell that I am getting weaker every time they strike. I know I won't be able to keep this up for much longer. " _I need to finish this. Now,_ " I tell myself.

I prepare my special attack. A hundred glowing spears materialize behind me. They shoot upwards and form a two-tiered circle, aimed down at the human. The deadly formation starts to spin before plunging downwards. A bright blue light radiates out as the projectiles make impact. When it dissipates, the human is standing there and holding their knife over their head like a shield. They survived.

I stare at them in utter disbelief. "How is that possible? You _couldn't_ have survived that attack!"

The human takes advantage of my momentary distraction and hurls their knife through the air. I feel it hit me and look down to see the weapon embedded in my chest. The human casually walks up to me and retrieves the knife, pushing me back in the process. I stumble and fall to the ground.

"I guess you're stronger than I thought," I remark. I know that I am slipping away again--my vision is starting to blur. " _No! I can't give up! I won't die! I WON'T DIE!_ "

My strength seems to return, and I stagger back to my feet. "It's not over yet. I can keep fighting you," I say.

"Oh, it is over," the human remarks, "Determination and monsters... it's a volatile mix."

Sure enough, my strength begins to fail again. My legs feel like they are turning to jelly, and I collapse, trembling. I see a few drops of blue liquid--the color of my scales--land on the ground. " _No. No! NO!_ "

My soul swells with the desire to live, to keep fighting. I try and find a remnant of the strength I had just moments ago, but I simply keep getting weaker. The blue drops are falling faster. I feel like I'm turning into a puddle.

The human smirks at me, their eyes glittering with triumph. "I'll give you something to think about as you die." They lean over me and stare directly at me, their gaze seeming to pierce my soul. "You have _failed_." They turn and begin to walk away.

"I haven't failed."

"I'm sorry, what did you say?" the human looks back and inquires.

"I haven't failed," I repeat. I'm smiling now, even though my voice is getting weaker. "While we've been fighting, Alphys has been evacuating everyone. You'll never get to them. So you see... THIS WORLD WILL LIVE ON!"

The human scoffs. "Goodbye, Undyne." They walk around a corner, and are gone.

I don't even have the strength to hold myself up anymore. I lie on the ground, each of my breaths more shallow than the last. I know that I'm dying, but I'm not scared--just disappointed that I couldn't stop the human. I clutch my spear tightly in my hand as my eye closes. " _Papyrus, I'm sorry that I couldn't avenge you. And Alphys... there are so many things I wish I'd told you._ "

With those last thoughts my mind slips away and my body crumbles to dust.


	2. Stick to Plan B (Alphys)

**Summary for the Chapter:**

> In the wake of Undyne’s death, Alphys struggles with her grief and the fact that the responsibility of stopping the human now falls to her and Sans.

**Notes for the Chapter:**

> Do you ever look back at something you did and internally scream with the desire to fix it?

I am curled up in a ball on the floor of my lab in front of the monitor, weeping. Sans is sitting next to me with his arm around my shoulder. "Alphys," he reassures me, "We'll get that human, I promise."

I look up at him, my eyes filled with tears and rage. "I am going to make them pay for what they did."

I stand up and begin walking towards the door.

"Alphys, where're you going? It isn't safe out there!" Sans tells me.

I pause and, without looking back, I inform him, "I am going to find that human, and I am going to kill them."

A latticework of bones appears before the exit, blocking my path. "I can't let ya do that."  
I look back at Sans and say, "Do not try to stop me."

"Alphys, there's no way that you'll be able to take on that human. Even Undyne couldn't stop 'em. You'll die in an _instant_." Sans's eye sockets are completely dark.

"They murdered my best friend, Sans!"

"And they killed my brother!" Sans's voice is shaking. "You don't think I want that human dead? I found Papyrus's remains out there in the snow! You can't even imagine what it's like to find your little brother's dust!" He looks down, and his eye sockets return to normal. In a quieter voice, he continues, "You're not the only monster who's lost someone."

"Sans, I-I'm so sorry. I-I shouldn't have s-said that."

Sans rests his hands on my shoulders and looks into my eyes. "They'll pay for what they did, Alphys. I promise you, they're gonna have a bad time."

I sniffle, and a tear falls to the floor. I ask, "C-can we at least go and bring U-Undyne's spear and d-dust back? She deserves a proper f-funeral, and... I-I want something to remember her by."

Sans replies, "I don't think we can. We'd probably run into the human on our way there, and we're supposed to be evacuating everyone. That was the plan."

"I-I didn't think that we were going to have to u-use it." My voice cracks, and I continue, "I thought she was u-unbeatable."

Sans nods his head sadly in agreement. I look back up at the monitor, and Sans follows my gaze. "Undyne'd want everyone to be safe more than she'd want her death avenged, and ya know that, Alphys. You should go power up Mettaton."

"I will. Can I p-please just have a moment, first? I need to say g-goodbye," I say.

Sans gives a quick nod. "I'll be in the other room. Lemme know when you're done," he tells me before leaving.

I walk over to the large monitor and rest my hand on the screen. All that remains of the monster I cared about more than life itself is a pile of bluish-grey dust and a glowing spear. I am wracked by silent sobs as I think, " _You saved me, that day we first met. I would have jumped if it weren't for you, Undyne. Now you've fallen, and I couldn't do a thing to stop it._ "

I walk over to my desk and open one of the bottom drawers. There is a rope inside, which I pick up. I grab a pen and paper as well. I walk over to the elevator leading to my true lab and step inside. Before I push the button though, I stop. " _I can't do this. Not yet._ " I head over to the corner where Mettaton is charging and activate him. " _There's work to be done._ "


	3. Filled with Determination (Undyne)

**Summary for the Chapter:**

> Stuck in a void between this world and the next, Undyne meets a mysterious new ally.

**Notes for the Chapter:**

> Italics. Everywhere.

I am floating in an endless void, trapped somewhere between consciousness and oblivion. Every once in a while, fragments of memories drift through my mind, although they seem like little more than dreams at this point. Overall, this place seems quiet and peaceful--no responsibilities, nothing to worry about. " _This is nice, I guess,_ " I think in my half-wakeful state. " _Maybe I should just rest for a while..._ " The already dim memories start to fade, and I sink deeper into the abyss.

Suddenly, a voice that is not my own speaks in my head. " _Interesting. I thought that you were the one monster who would never give up._ "

The abrupt appearance of the voice and this odd statement are enough to pull me at least a little ways out of the limbo-like state that I was beginning to enter. Mustering as much focus and willpower as I can, I ask, " _Who are you? How are you here?_ "

" _You could say that I am a friend. A partner, even. As for how I am able to be here... well, I'm in a similar situation to you,_ " they explain.

" _You didn't exactly answer my questions._ "

" _I did. You are just unsatisfied with what I said._ "

After a second, I reply, " _Fine. But you owe me another question._ "

" _You are not the one in control here, but I suppose I will humor you,_ " the mysterious voice responds.

" _Why are you here? You don't seem like someone who would just strike up a random conversation, especially if you're, well, dead,_ " I inquire.

They respond, " _We have a mutual enemy, Undyne._ "

" _How do you know my name?!_ " I shout. This takes a lot of effort and leaves me almost exhausted--if a monster in my condition can even be exhausted.

" _Be careful not to overexert yourself. It takes quite a bit of effort to bend the rules of the void, and we haven't finished our conversation yet. To answer your question, like I said, we have a mutual enemy. A mutual enemy whom I can't stop alone,_ " the voice discloses.

I ask, incredulously, " _You want my help? I'm DEAD! What exactly do you think I can do?_ "

" _With a bit of my assistance you will be capable of quite a lot._ "

" _What's that supposed to mean?_ " I question.

They promptly answer, " _It means that I have an offer to make you. It's mutually profitable, and it would give you another chance to save your friends and stop that human._ "

" _How? I fought them with everything I had and it still wasn't enough. There's nothing more I can do,_ " I explain.

" _Unless, of course, I bring you back,_ " they state.

" _That's not possible. Nobody can come back from the dead._ "

" _There might be a way,_ " the voice assures, " _if you trust me. I don't know if it will work, and I doubt that you will be able to maintain your form permanently, but I believe that I can let you live again. For a little while, at least._ "

" _If whatever you're planning will allow me to keep my friends safe, I'll do it,_ " I say determinedly.

A pinprick of light appears in the darkness of the void. " _And you are sure you are prepared?_ " my mysterious companion inquires. I can hear a note of concern in their voice.

" _Yeah. Let's do this._ "

" _Very well._ "

I begin to feel that strange, burning power from my fight with the human. It grows in intensity with every passing second, and the light brightens along with it. The abyss around me disappears and the familiar sounds of Waterfall fill my ears.


	4. Megalovania (Sans)

**Summary for the Chapter:**

> A human with nothing to lose meets a skeleton with everything to fight for.
> 
> The day of judgement has come.

I stand in the hallway before the throne room, the sunlight streaming through the large, elegant windows. I hear the clicking of shoes on the stone-tiled floor and see movement at the end of the room. The human steps out into the light. " _Welp. Guess they made it past Mettaton. I hope Alphys didn't try to stop them,_ " I think.

The human walks forwards and stops a few feet away from me. "Don't take another step, buddy," I warn them, "You won't like what's comin'."

They pointedly step forward. I sigh and look out one of the windows, saying reflectively, "It's a beautiful day outside. Birds are singing, flowers are blooming... On days like these, kids like you..." I suddenly turn back to the human, one of my eye sockets glowing a bright blue and yellow. "SHOULD BE BURNING IN HELL!!!"

Bones materialize on the floor and ceiling, and the human barely manages to leap out of the way. Before they have a chance to recover, Gaster Blasters appear behind me and fire on the human, who is knocked flat on their back. Somehow, though, they find the strength to stand up and lunge at me with their knife.

I sidestep out of the way and they sail past me. The human turns about and says to me, "For someone who supposedly has very weak attacks, you do quite a lot of damage."

"Well, I guess ya could say that I'm just giving you what you've got coming."

They reply, "I was wrong to think you'd be an easy kill. Oh well, this is more fun anyway."

I take advantage of this momentary lull in the action to send another wave of bones flying at the human, which they miraculously manage to dodge before taking another unsuccessful swipe at me.

We repeat this process over and over--attack, dodge, attack, dodge. I can't seem to seriously injure the human, nor can they land a blow on me. I can tell this strategy isn't working. " _Time for something new._ "

My socket flashes brighter and the human slams into the ceiling before plunging back to the ground. They shakily stand back up and proclaim, "You certainly are full of surprises, aren't you Sans?"

Our battle continues. I keep changing up my attacks to catch the human off guard. It works for a while, but eventually they begin to get better at dodging, as if they are learning my patterns. I'm starting to get exhausted. "Buddy, please. I don't wanna use my special attack. Neither of us are gonna like that. So, can you just go ahead and DIE ALREADY?!?"

I throw everything I've got at them--Blasters, bones, my entire arsenal--but the human just won't give up. In a last-ditch effort, I slam the them against anything and everything in the corridor. When I finally can't muster the energy to attack anymore, the human is still standing. They try to stab me again, and I just barely manage to duck the blow in time.

"Well," I tell the human, "Here goes nothing."

They stand there expectantly for a few moments before saying, "Get on with it! Use your special attack!"

I respond, "This _is_ my special attack. It's nothing. See, you've got an odd habit of fighting in turns. That means if I don't attack, you can't retaliate. I'm prepared to stand here forever, what about you?"

The human twirls their knife frustratedly, but doesn't make a move. We stand this way for several minutes. The fight has exhausted me, and I start to nod off despite my efforts to stay alert. I don't get a long time to rest however, as the human defies their own logic and attacks me. I wake up just in time to see the cruel blade descending over my head. I make a desperate leap to the side and declare, "You're very deter--"

The human raises their knife again, and before I can react, the blade begins its descent. Less than a second before I am slashed from shoulder to hip, something strikes the weapon and sends it flying out of the human's hands. It thuds into the wall and sticks there, quivering. The unknown projectile slams into a column next to the knife, allowing me to get a better look at it. The object that saved me was a glowing energy spear. A familiar voice calls out, "Need some help, Sans?"


	5. Spear of Justice (Undyne)

**Summary for the Chapter:**

> With one last shot to take down the human, Sans and Undyne give their all to make it happen.

**Notes for the Chapter:**

> Got a bit of a longer chapter this time!

I step out from the shadow cast by one of the pillars. Sans stares at me in shock. Even the human is wearing a rather surprised expression.

"Undyne...? It can't be you. I saw them kill you," Sans states as he gestures at the human.

"I'm not sure exactly how I came back. I just know that someone did something to help me and I woke up in Waterfall," I explain.

The human chuckles. "But you aren't _really_ back, are you? You're still just dust. You won't be here for much longer." They point to my scales, which are now only the faintest blue color. They have taken on a different texture as well--soft, almost powdery.

"Maybe so, but I plan on sticking around long enough to get rid of you," I respond.

Sans steps forward and says, "I'm not gonna let you do this. This human beat you before, and I'm sure they could do it again. I'm not gonna let you throw away this chance to keep living."

I look at him, a solemn smile on my face, and reply, "Sans, I've already been turned to dust. If I lose this fight then I'll probably be no worse off, and I want to do everything I can to save all of you."

Out of the corner of my eye I see that the human is inching over towards their knife, which is still embedded in the wall. Our eyes meet for a moment before we both sprint to grab our respective weapons.

The human reaches their blade before I do, but they have some trouble pulling it out of the wall. I reach my spear a split second later, but I'm able to remove it from the pillar it's lodged in much more easily.

We turn to face each other, and I ask, "Ready for round two?"

"Of course," they answer with a malevolent grin, "Getting to kill someone twice is a nice treat."

We stand several feet away from each other, and I assess the situation. I am wearing armor and have a longer weapon than the human does, which gives me an advantage. However, the human is a bit faster than I am and is obviously quite agile. They've also seen me fight, so it will be harder to surprise them. " _Well, at least I know how they fight, too,_ " I think.

The human starts our battle by quickly closing the distance between us and lunging with their knife. I pivot out of the way and jab my spear at them as they pass by.

They must have been expecting this, however, because they manage to dodge my strike. I quickly follow up by sweeping the point of my spear in front of their feet, which causes them to stumble. Before the human can recover, I try to stab them. My spear strikes true, but they pull away before much damage can be done.

The human spins around and says to me, "Interesting new idea. But if you think a few stab wounds will stop me, well... I'd just have to say that you're wrong."

They lift the knife and flick their wrist, sending the deadly blade flying my way. I recognize what the human is trying to do and fling myself out of the weapon's path. I almost manage to completely evade the attack, but the knife grazes my neck as it shoots by.

I gasp from the pain and reflexively reach to cover the wound. To my surprise, I can feel no blood leaking from the cut. I pull my hand away and see that it is coated in a fine layer of powder.

The human smiles maliciously and announces, "It's as I expected. You are not long for this world."

I clench my hand into a fist and grin back. "Well, I'll just have to settle for taking you with me when I go, then."

Glowing spears appear behind me and I launch them at the human. They dodge them all and run behind me to grab their knife. I send another volley of magical projectiles after them, but the human reclaims their weapon and slices them out of the air.

They charge at me and I hold my spear in a defensive position, planning to attack once they are in range. Before the human reaches me, though, light fills the hallway as a Gaster Blaster materializes over my shoulder and fires on them. The human just barely manages to raise their knife in time, which absorbs the energy of the attack.

Without taking my eye off of the human, I yell, "Sans, stay out of this! You know how easily you get hurt!"

He steps up beside me and replies, "Heh. I actually think we have a better chance of taking them down together, don'tcha think?"

I hesitate, then sigh. "Well in that case, why didn't you join in earlier?" I ask with a grin, glancing at him.

Sans gives me a shrug and explains, "What, a skeleton can't stop to catch his breath for a minute around here?"

The human fidgets impatiently with their knife and asks us, "Are we going to get back to fighting anytime soon?"

In response, Sans's eye flashes and the human flies up into the air, smashing against the ceiling before crashing down again. Before they can get up, I rush forward and attack with my spear. Right before my weapon makes impact, the human raises their knife and tries to deflect the blow. Instead of hitting their head as I had intended, the spear scrapes along the human's shoulder.

The human rolls over and stands up, evading another swipe from my spear. They strike back, and the point of their knife manages to find a small gap between the plates of my armor, wounding me once again. Luckily, the cut isn't too deep.

In retaliation, I drive the point of my spear towards them. It opens up a small wound, but the human moves backwards. Sans, seeing this, makes a ring of bones rise out of the ground behind them.

The human continues to retreat, unaware of the trap waiting right behind them. They step into the circle and Sans generates more bones. They form a cage around the human, trapping them inside.

Sans looks to me and asks, "Do you wanna finish them off?"

I turn to him, smile, and respond, "Together."

Bones and spears appear, all of them aimed at the human. At our command, they hurtle towards their target. The human manages a brief expression of defiance before they are struck with the magical attacks.

When the energy of the combined attacks fades, the human is lying on the ground--knife by their side. Shakily, they raise their head. I walk over to them and stand, looking down. The human is clearly dying, but they obviously don't want to give up, either. They ask me, "Well, what are you going to do now?"

I raise my spear and position it, point down, above the human.

"Oh, do you really want to kill an unarmed child, Undyne?" they inquire sweetly.

I plunge my spear straight into the human's heart and proclaim, "You don't deserve mercy."

As blood begins to flow from the wound, they gasp, "One way... or another... I _will_ be back." The light fades from the human's eyes, and they lie still. Slowly, a glowing red soul floats up out of their body and hovers a few inches above the human's chest.

I step back and turn to Sans. "We did it."

Sans chuckles. "Sure seems that way." After a second, he frowns and continues, "Hey, are you okay? You look like you're not feelin' too good."

I've sat down on the ground beside the dead human, my head drooping forward slightly.

Sans rushes over, crouching down next to me. "Undyne, what's wrong? It didn't look like the human hurt you _that_ badly."

"No, Sans, that's not why this is happening," I explain, "I'm on borrowed time."

He pauses before asking quietly, "So, you aren't gonna make it, are ya?"

I look into Sans's eye sockets and say, pensively, "I've done what I came to do. The human is dead. I think that the only reason I was able to keep myself from turning back into dust was that I knew I had to stop them. Now that they're gone... I don't think I can really tap into the power that allowed me to stay alive anymore." I've begun to slowly disintegrate.

Suddenly, Sans says, "I've got an idea."

Sans looks to where the human's soul is floating. I follow his gaze and say calmly, "Sans, I'm at peace with this."

"But I'm not," he replies, "And you may not think that you have any reason to keep going, but you do. Think about Alphys--you mean everything to her. Stay alive for her."

Hearing Alphys' name fills me with that now-familiar feeling again. I reach out and grab the human's soul. The sheer strength of it burns my hand on contact, even through my armored glove. Still, I grit my teeth and hold on. After a few seconds, the stinging fades away as the soul is absorbed.

"Did it work?" I hear Sans ask.

I stand up, completely healed. "Come on, we need to get back to Alphys," I say as I stride purposefully out of the hallway.

Sans stands up and replies, "I'll meet you at the lab. I'm gonna go tell Asgore the good news."

I exit the corridor and begin running back to Hotland.


	6. How to Save a Life (Undyne)

**Summary for the Chapter:**

> Alphys was afraid she wouldn’t be able to go on, now Undyne is afraid she’s too late to save her.

**Notes for the Chapter:**

> Just a warning, this chapter deals with a pretty heavy subject.

I finally reach Alphys's lab. I am out of breath from the run, but I pound on her door and shout, "Alphys! Alphys, it's me, Undyne! I'm okay! It's a long story, but I can explain. The human is dead and everyone is safe. Please, let me in!"

There is no response, so I try again. "Alphys! It's really me, this isn't a joke! Let me in!"

I wait for about a minute longer before thinking, " _Where is she? I know that she would have let me in by now. And she would_ never _have left the lab unattended, even if the human was coming through._ "

I try and open the door, but it is locked. "Alphys, are you in there?" I call out. The only response is an eerie silence and the distant bubbling of lava. " _Something is very, very wrong._ "

I wedge my spear into the gap between the door and the frame and push on it with all my strength. The door groans and slides open, allowing me to slip inside.

The lab is deserted--I don't see a trace of either Alphys or Mettaton. I look around for a minute before seeing a note taped to the bathroom door. I walk over and read it.

**To whoever finds this,  
**

**If you get this note then don't expect to find me. I've hanged myself. I just couldn't go on anymore. My two best friends in the entire world, Undyne and Mettaton, are dead. I watched them die at the hands of the human, and I couldn't do anything to stop it.  
**

**Without them, life isn't worth living. Mettaton was my dear friend and brought so much light into my life, without judgement for my mistakes. Undyne... meeting her was the best thing that ever happened to me. I don't think she knew, but I was planning on jumping into the abyss that day we met. We became such good friends, which is why I never told her the truth about who I am. Now I guess that I never will get that chance.  
**

**Behind this door is an elevator that leads to my true lab. Soon after I was appointed as the new Royal Scientist I started working on some experiments with determination. I injected it into some monsters who had fallen down, in an attempt to see if their souls would persist after death. They woke up instead. At first, things were fine, and I even told the families that their loved ones would be coming home.  
**

**Then they started melting. It turns out that monsters are unable to handle as much determination as humans can, their bodies just can't handle the strain. The monsters that I had experimented on wound up fusing together into amalgamations.  
**

**The amalgamates are down in my true lab. I would like you to take care of them. They don't deserve what they've gotten, and I don't want them to suffer anymore because of me. It's time everyone learned the truth. I'm sorry, I never meant to hurt anyone.**

**\- Alphys**

By the time I've finished reading the note I feel like I'm going into shock. " _Alphys cannot be dead. SHE CANNOT BE DEAD!_ " I think. I open the door and step inside the elevator. I press the button, and the elevator whirs softly as it descends.

When the door opens, I am greeted to a startling sight. There is a massive monster blocking the exit of the elevator. It looks like a bunch of dogs all stuck together. The amalgamate stares at me passively. " _This must be what Alphys wrote about._ "

I try and push past the creature, but it plants its feet firmly on the ground and refuses to let me through. It's acting as if it's trying to guard something.

"Please!" I scream desperately, "Please let me through! I need to find Alphys, I need to get to her!"

Something in the creature changes, as if it understood what I said. It steps to the side, and I run past it, out into the corridors of the lab. I frantically check every room, but to no avail. I can't find Alphys anywhere. " _It's going to be too late! I need to find her now!_ "

After about a minute of searching, I reach the last unchecked room. I throw open the door to a terrifying sight. Alphys has hung herself from the ceiling, and she seems unconscious.

"ALPHYS!!!" I yell. I throw my spear, which severs the rope and causes Alphys to drop to the floor. I rush over to her. Her eyes are closed, and she is perfectly still.

I cradle her in my arms and say, "Alphys, you need to wake up. Open your eyes, or say something, or do _anything_! Just come back to me... Please..."

Still, she doesn't respond. " _I'm too late. I've lost her,_ " I think as I start to cry.

For a moment, I think that I feel a whisper of breath on the side of my neck. Then, Alphys's chest begins to rise and fall shakily. Her eyes flutter open, and she says in a hoarse voice, "U-Undyne?"

My heart skips a beat and I immediately pull her into a hug. "Alphys, you had me so scared. I was _so scared_."

As soon as I release her, she asks, "Am I d-dead?"

"No, Alphys, you're alive. You're alive. Everything's fine," I tell her, my voice cracking slightly.

"B-but you can't be here. I saw you d-die," Alphys replies.

"I'll explain that later. All that matters right now is that you're okay."

"D-did you find my note?" she inquires. I nod in response. "So, you k-know about the a-amalgamates? And that I l-lied to you? Y-you must be so angry with me."

I look into Alphys' eyes and reply, "I'm not mad at you. I just don't understand why you didn't tell me."

She explains, "I w-wanted you to l-like me. I thought that you wouldn't want to hang out with me anymore if you learned who I really am."

"Alphys," I answer, "I like you for exactly who you are. Nothing that you've just told me changes how I feel."

Alphys smiles--a real, genuine smile.

We sit in silence for a while, Alphys still cradled in my arms. Eventually, hesitantly, I ask, "Why did you try to... to kill yourself?"

Tears fill Alphys's eyes as she blurts out her explanation. "You were dead. I watched that human _murder_ you. Undyne, I just... I couldn't imagine a life without you! I LOVE YOU!"

I stare at her, wide-eyed, for a few moments. Alphys looks away and mutters, "I-I'm sorry. I-I shouldn't have--"

I lean down and kiss her. After a second of shock, Alphys kisses me back. "I love you, too," I announce. Both of us start laughing in relief and joy.

**Notes for the Chapter:**

> I’d just like to say I’m sorry if the way this chapter was handled comes across as kind of blunt, that wasn’t my intention. Emotional scenes have always been kind of tricky for me to do and I’m not always sure I get them right.
> 
> Other than that, I hope you all have been enjoying this story so far!


	7. A Triumphant Return (Undyne)

**Summary for the Chapter:**

> With the human gone and the evacuation orders lifted, the surviving monsters have congregated in Snowdin. Asgore and Undyne start planning how to rebuild the monster kingdom.

I hear feet pounding on the floor outside the room and look up. Sans bursts through the open doorway and skids to a stop. "What happened? The door looked like it was forced open, did the human get in before we stopped 'em?"

His gaze darts to the remains of the noose around Alphys' neck and he continues, "Alphys, you didn't..."

She looks down ashamedly and replies, "I d-did. Sans, I'm so s-sorry."

Sans stares at me and asks, "You saved her?"

I give a quick nod and Sans replies, "Good. There's already been way too much death today. Oh, and Asgore wants to talk to you, Undyne."

I sigh. "He's probably pretty mad about me taking the soul, isn't he? Now we might not be able to use it to break the Barrier."

"He actually seemed pretty relieved," Sans informs me, "He told me that he was happy you're alive, and even happier that we managed to stop the human, even if we're all still trapped down here."

"W-wait, you absorbed the human's soul?" Alphys inquires.

I explain to her, "I didn't plan on it, but Sans kinda insisted. And... I have a pretty good reason to stick around for a while." I pause for a moment before continuing softly, "I want to stay with you."

Alphys blushes and looks away from me, a tiny smile on her face. Sans breaks the silence by announcing, "Asgore told me that he's called off the evacuation now that the human's dead. He's planning on bringing all the monsters to Snowdin for a while. Said that he thinks people'll wanna stick together for a few days, and that there should be enough room in town for everyone."

"We should join them. I need to make sure that they're all okay and that they don't need anything," I say. "Alphys, do you think that you're strong enough to walk?"

She nods and replies, "I-I think so." 

Before she can get up, I lift the tattered loop of the noose from around her neck and toss it aside. "Th-thanks," Alphys says.

She stands up and shakily tries to take a few steps. I quickly walk over to her and put my arm around her shoulders to steady her. Alphys looks up at me and says, "O-oh. It's okay, I-I can walk on my own."

I shake my head and respond, "Just let me help you. Please?"

After a moment's hesitation, Alphys says, "Alright."

We start walking towards the elevator, Sans calls out, "Ya may not need to help her very far. I know a shortcut that'll bring us right to Snowdin."

He starts walking towards one of the doors and continues, "It's this way."

Alphys and I glance at each other questioningly before following Sans into one of the other rooms. We go through the door behind him and immediately emerge from the entrance of one of the underground tunnels in Snowdin.

"Fast shortcut, huh?" Sans says. 

I stare at him in confusion and ask, "Can you please tell me what just happened?"

Sans grins. "I told you," he explains, "We took a shortcut."

I am about to reply when Alphys interrupts, "L-look! Everyone's here!" She points to the end of Snowdin, in the direction of Waterfall.

Sans and I both look over, and, sure enough, there is a procession of monsters heading our way. Even from this distance, I can see that Asgore is leading them. I begin walking towards the group at a brisk pace with Alphys and Sans following along behind me.

Asgore and I walk until we are a few feet apart, then stop. "Howdy, Undyne," he says.

I ask, "Did everyone evacuate in time?"

Asgore shakes his head slowly before responding, "Many did, but some monsters chose to stay behind. They wanted to give their families more time to escape."

I look down at the ground and say, "They shouldn't have done that. It's not their job to protect people."  
Asgore rests a big, furry hand on my shoulder, and I look up at him. "You did all you could to stop that human," he reassures me, "and from what I heard, it was quite a lot."

I am about to reply when someone in the crowd shouts, "UNDYNE!" A few seconds later, the little yellow monster kid slams into me. After a moment, he steps back and starts bouncing around happily, yelling, "Yo! You're alive! I knew you could do it, I knew you could stop the human! You're the strongest monster EVER!"

I smile and chuckle at his statement. "Thanks, kid."

He jumps around for a few more moments before explaining, "I need to go find my parents now. Bye, Undyne!"

He runs off, and I admit to Asgore, "I'm glad the kid's alright."

"You have always been a caring monster, even if you do not like it admit it," Asgore notes. I grin and punch him in the shoulder.

"I must go now," he continues with a chuckle, "I need to head back to the capital and start the process of cleaning up this mess that the human has left behind."

Asgore turns and starts to walk away, but stops and says over his shoulder, "Oh, and I have a favor to ask of you."

"What do you need me to do?"

Asgore turns back so that he is facing me again. "It is going to be a lot of work, rebuilding the Underground. I will not be able to do it alone. I am going to need someone to manage affairs in the places farther from the capital, and as captain of the Royal Guard you are the most qualified for the job."

"I'll do it," I answer.

Asgore smiles and says, "I thought you would agree. Now I really should be on my way, I have business to attend to. And by the expressions, on your friends' faces, so do you."

I turn around to look at Alphys and Sans, who have been watching the conversation. Both of them look like they want to talk to me, so I walk over. "What's up?" I ask.

"I think there's some stuff all of us need to talk about," Sans announces. "So I was wonderin' if you two girls would like to go to Grillby's?"


	8. A Solemn Promise (Undyne)

**Summary for the Chapter:**

> Undyne, Alphys, and Sans discuss the implications of Undyne’s determination and the human’s soul.

**Notes for the Chapter:**

> Last chapter, everyone! I hope you enjoy it!

Alphys, Sans, and I walk into the small bar. Since the inhabitants of Snowdin just arrived, the restaurant is deserted. Sans sits down on one of the stools at the bar. Alphys and I follow suit.

After a few seconds of awkward silence, Sans begins to speak. "We need to talk about some things. For starters, I think you owe us an explanation, Alphys."

Alphys squirms uncomfortably in her seat and averts her gaze. I rest my hand on her shoulder and whisper, "It's alright. Just answer his questions."

After a moment, Alphys asks, "W-what do you want me to tell you?"

Sans replies, "Well, it sorta looks like Undyne might want to ask you something."

Alphys glances over at me and asks, "I-is there something th-that you want to know?"

"Yeah," I reply, "Alphys, what exactly are those creatures in your basement? You said in your note that they were monsters?"

"Th-they are monsters. When I first became the Royal Scientist, I did experiments with d-determination on monsters that had fallen down. Instead of allowing their s-souls to persist after death like I h-hoped, it brought them back. B-but their bodies couldn't handle it, and they melted into the creatures you saw," Alphys explains. "L-like I said in my n-note."

"And you haven't told anyone besides us, have ya?" Sans inquires.

Alphys shakes her head. "O-only Mettaton. I-I just didn't want people to be mad at me. Th-they would fire me and d-drive me away and... and..."

Alphys looks like she is about to start crying. Sans seems to notice this and asks in a gentler tone, "Is that why you tried to commit suicide?"

"N-no..."

"Well, what was the reason, if ya don't mind telling us?"  
Alphys sniffles and mumbles, "I-it was because... the human... the m-monsters I cared most about were d-dead." Alphys starts to cry quietly and continues, "I-I couldn't, I j-just couldn't..."

I give her a hug and say to Sans, "I think you should let up on the questions for now."

"That works," he replies, "I need to ask you about some stuff, too."

"Such as?"

"The fact that you're clearly not a normal monster."

"Sans, is that a question or an insult?" I retort.

"It leads to a question," he tells me. "Which is, how're you alive right now? You were dead, but you came back. It shouldn't be possible."

I shrug. "Well, I absorbed the human's soul. I'm pretty sure that's why I'm still here."

"I agree, but how did you come back in the first place? Alphys and I watched you die."

I pause for a moment before answering, "I'm not sure what exactly brought me back. I just know that someone did something to help me."

"Hmm... But how did you stay alive? Why didn't ya just turn back into dust?" Sans asks.

"D-determination. You have determination, Undyne," Alphys interjects.

I look at her and respond, "But you just told us that it's not possible for monsters to have determination."

"M-most monsters don't. B-but some, such as Boss Monsters like Asgore, are able to handle trace amounts. Th-that's what allows their souls to persist after death for a few seconds," Alphys explains to me.

"But I'm not a Boss Monster," I respond.

"That's what I'm confused about," Sans states.

Alphys continues, "I-I'm not sure why you have determination Undyne. M-maybe there's something about your physiology. S-something that makes you stronger than other monsters."

"Whatever the reason," Sans says, "It'd be very helpful to understand exactly how it's possible for a monster to have so much determination."

"I-I could run some tests," Alphys suggests, "Th-that is, if you don't mind, Undyne."

"I don't mind. To be perfectly honest, I'd like to know more about this 'determination' thing, too," I say.

Alphys smiles. "O-okay! Um, when you have some free time, j-just stop by my lab, then!"

I give her a toothy grin in response. "I'll do that."

Sans begins to say something, but the door opens and he stops to look over. Grillby walks into the restaurant.

"Oh, hey Grillby. Gettin' ready to reopen?" Sans asks. Grillby gives a small nod, and Sans replies, "Okay, then. We'll get out of your way."

He stands up and exits the restaurant, saying as he leaves, "Alphys, Undyne, I have some stuff to do. I'll see ya later, girls."

I look at Alphys and suggest, "We should probably head home. I don't know about you, but I'm _exhausted_."

"A-alright. I guess I'll see you later, then?" Alphys responds.

"Yeah. I'll come over to your lab whenever I get a day off, okay?"

Alphys nods, and I get up to leave. I'm almost to the door when I hear her shout, "W-wait!"

I turn around to ask Alphys what she wants when she pulls me into a hug and quickly kisses me on my cheek. She steps back, blushing, and says before rushing out the door, "B-bye, Undyne!"

I glance over to Grillby, who is now standing behind the bar. I realize that he probably saw everything that just happened and feel my cheeks start to flush. 

"Um, bye Grillby," I mutter before stepping out into the cold snow.  
I stand outside the restaurant and look around Snowdin. Various monsters are trickling back to their homes. Others stand uncertainly in the town square, as if they are still afraid that the human will leap out and ambush them. I feel my newly-absorbed human soul pulse with determination.

" _I will protect you. All of you,_ " I vow to myself, " _I will fight to my dying breath to keep you safe. No human will hurt you ever again._ "


End file.
